Lundin completes Gohta appraisal well in Barents Sea
STOCKHOLM, Sweden -- Lundin Petroleum, through its wholly-owned subsidiary Lundin Norway, has announced that the drilling of appraisal well 7120/1-4S, in the western part of the Gohta discovery in PL492, has been successfully completed. The well was drilled 5.3 km northwest of the original Gohta discovery well.
The main objectives of well 7120/1-4 S, which was operated by Lundin Norway, were to confirm the extent and reservoir properties of the Permian carbonates and to establish the oil-water and gas-oil contacts in the western parts of the structure.
The well encountered 10 m of Upper Permian limestone conglomerate with good reservoir properties overlying fractured limestones of limited reservoir quality. The conglomeratic interval contained gas condensate and the limestone contained traces of oil but appears to be tight. The depth interval of the oil traces in the appraisal well corresponds with the oil column in the 7120/1-3 discovery well.
Extensive data acquisition and sampling was carried out in the reservoir, including conventional coring and fluid sampling.
The pressure and fluid properties indicate communication between the reservoirs in the two wells on the Gohta structure.
Two production tests were performed in the well. An attempt was made to test a 50 m interval starting 23 m below the estimated gas-oil contact followed by a test of the 10 m thick conglomerate interval. The oil zone test instantaneously produced gas at a rate of 6.4 MMcfd. Pressure build-up data showed drainage from a porous reservoir as a result of insufficient isolation between the oil and gas zones on the outside of the production liner. The oil zone test was therefore not conclusive.
The test of the 10 m thick gas condensate zone produced 26.4 MMcfd of gas and 880 bpd of condensate. The pressure build-up analysis showed the test draining an area with a radius of at least 1,000 m out from the well. The results confirmed good production characteristics in the matrix of the limestone conglomerate.
Appraisal well 7120/1-4 S is the second well drilled in production license PL492 after it was assigned in 2008 (APA2007). It was drilled to a total depth of 2,490 m below sea-level. The water depth was 331.5 m.
The well was drilled by the drilling rig Island Innovator. It will be permanently plugged and abandoned before the rig proceeds to drill exploration well 7220/11-1 in production license PL609 where Lundin Norway is also operator.
The Gohta discovery well 7120/1-3 was completed in October 2013 and found a 25 m gross gas column above a 75 m gross oil column in karstified and dolomitized limestone. The well production tested approximately 4,300 bopd through a 44/64-in. choke and the preliminary evaluation of the gross recoverable oil and gas resources from the Gohta discovery well is estimated at between 111 and 232 MMboe.
Lundin Norway is the operator and has a 40% working interest in PL492. The partners are Det norske oljeselskap ASA with a 40% working interest and Noreco Norway AS with a 20% working interest.